Separable sieve for bolters



Nov. 28, 1939; w. E, NORVELL SEPARABLE SIEVE FOR BOLTERS Filed 00f 21 1936 2 Sheets-Sheet 2 .2... Q :0. vvvv.

INVENTOR WILL/AM E. NORVfiLL WE /a014, ATTORNEY Patented Nov. 28, 1939 UNITED STATES [PATENT OFFIQE 5 Claims.

My invention relates to sieves for bolters, and more particularly to separable, or demountable, sieves for such bolters.

, In all stack sieve bolters, or sifters, used in 5 flour mills, which are provided with sieve frames havingmetal pans, wire cleaner cloth and silk bolting cloth, these parts have all been made so as to be permanently connected together by means 7 of one frame, which necessitated a large amount 10 of labor to tear thesa-me apart to make necessary repairs to the sieve. These sieves were, of course, arranged in stacks to form the bolters, or sifters, and while each sieve could be removed for repairs, the sieve itself was difiicult to repair and 15 required the taking'apart of the structure of the frame and of the other parts of the device to get at the parts that most frequently required replacement. The parts that most frequently required replacement in such sieves were the reticu- 2 lated wire clothed members that formed a perforated partition between the bottom of the pan portion of the sifter and the silk bolting cloth for retention of cleaning devices adjacent the silk bolting cloth, said retaining devices being loose metal members, usually of a bolt-like character, which also at times required replacement. In taking off the silk bolting cloth to get at the wire member of the sieve, the silk frequently was damaged and had to be replaced, where it would otherwise not have been necessary, as, of course, any

holes in the silkwould render the same absolutely useless.

It is a purpose of my invention to provide a sieve which avoids the above difficulties, by providing a demountable inner frame, or tray portion, which can be readily removed and replaced with a similar frame, or tray portion, and then repaired at leisure, said demountable tray, or frame portion, carrying all the parts that usually the silk bolting cloth and the loose cleaning members between these two. This makes it possible to repair any parts that may be damaged and require replacement, very quickly, with minimum 45 shut down of the bolter, and permits the repair at odd times while the bolter is in operation, of the inner frame-like members, or trays, so as to have the same ready when the next shut down of the bolter occurs, said frames being inter- 50, changeable and being so made that these can be used with the body portions of the sieves with which the same cooperate, no matter whetherthese may be rights or lefts. Thus in bolters, of the character in which sieves forming the'subjeot 55, matter of this invention, are used, the arrangeneecl repair, such as the reticulated wire portion,

ment of passages in the body portions of the sieves is frequently reversedso that the flour can be directed through the same in any desired path, in some cases the passage feeding flour to the next lower sieve is" located to the left of the passage that feeds the bolted flour ou't'of said sieve, while in other cases this feeding passage leading to the lower sieve, is located at the right of the passage through which the bolted flour is to pass, thus providing theleft and right type of body portion, above referred to.

- My improved bolter sieve more particularly comprises a body portion and a removable inner frame, or tray portion, that are so connected together that the same aredetachable from each other, but when in position, form tight joints between said tray portion and bodyportion of the sieve wherever needed to prevent passage of flour in a direction that would interfere with the proper operation of the bolter, that is, to prevent passage of flour that has not passed through a certain bolting silk of a certain sieve from becoming mixed with the flour that has passed through said bolting silk. In order to accomplish this, tightly interfitting portions areprovided on the detachable inner frame, or tray portion, and the body portion, which are all interlocked in substantially dust-tight relation to each other when certain fastening devices are put in position for securing the inner tray portion and the body portion together detachably.

It is a further purpose of my invention to provide a sieve of the above mentioned character having removable tray portions that are so constructed and arranged that it is unnecessary to v remove the plush used for obtaining a tight joint between the adjacent sieves in the bolter, nor the bolting silk, in order to remove said tray-like members. Furthermore, by my improved construction, the reticulated wire member, known 4 commonly as the back wire is more securely and tightly held in position than has been previously the case, obtaining a better cleaning action from the loose cleaner members, above referred to, and furthermore the mounting of this wire member is such that the cleaners can be changed without removing any of the tacks, or other means, used for holding the silk, thus preventing any damage to the silk when cleaner members are to be removed and replaced by other cleaner members.

Other objects and advantages of my invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown or described, except as defined in the claims.

In the drawings:

Fig. l is a top plan view of one of my improved sieve members.

Fig. 2 is a similar view of one of my improved sieve members with the feed passage thereof arranged on the opposite side thereof from that shown in Fig. 1.

Fig. 3 is a vertical sectional view on an enlarged scale through a pair of my improved sieve members-arranged in stacked, or super-imposed relation, the upper sieve member being one of the type shown in Fig. l, and the section being taken substantially on the line 33 of Fig. 1, and the lower sieve member being one of the types shown in Fig. 2, and the section through said lower sieve member being taken substantially on the line 3--3 of Fig. 2.

Fig. 4 is a section on an enlarged scale, taken substantially on the line 4-4 of Fig. 1.

Fig. 5 is a fragmentary top plan view of the sifter shown in Fig. 1, with the tray portion removed, and

Fig. 6 is a fragmentary plan view of a portion of the sifter shown in Fig. 2 with the tray portion removed.

Referring in detail to the drawings, my improved sifter comprises a body portion having outer side walls I0, II, I2 and I3 forming a rectangular frame. Spaced by means of suitable spacing blocks from the frame member I0 is a partition member I4, one of the spacing members being shown at I5 in Figs. 1 and 2. An upstanding rib, or tongue, I6 is provided on the member I4. A strip I1 is provided on the frame member I2 to provide a shoulder, or offset, on said body portion, running along said frame member I2, but depressed below the top edge thereof for reception of the removable tray member, and a groove I8 running lengthwise of the frame member I2 on the inner face thereof above the ledge, or shoulder, thus formed by the member I1, is provided for receiving a tongue on the detachable tray member, which will be described below.

A partition member I9 is provided, spaced from the frame member I I by suitable spacing means, such as the spacing blocks 20 and 2|, said partition member having a strip 22 secured. thereto, to provide shoulders on said partition l9 running lengthwith thereof spaced from the top and bottom edges thereof, the top edge of the partition I9 being made in the form of a tongue, or rib, 23 running the full length thereof between the frame members III and I2. A low partition member 24 is provided, spaced from the frame member 53, said low partition member running the full length of the body portion between the frame members II} and I2, but a portion of said partition is provided with an upwardly extending portion 25 of greater height than the main portion 24 thereof, extending just beyond the partition 54 from the partition I!) and being provided with a rib, or tongue, 26 on the top edge thereof.

A bracing member 2? is provided, which extends from the frame member ID to the frame member I2, extending under the spacing member I5. A bracing member 28, extending perpendicular to the bracing member 27, is also provided, extending from the member 22 over the member 24, being secured to both said members. A sheet metal bottom member 29 is secured by any suitable fastening means, such as the nails 35, to the top face of the member 24 and the bottom faces of the members 28, I4, I? and 22, and to the top face of the bracing member 21. Thus the bottom Wall 29 is provided for the body portion of the sieve, which is spaced from the bottom of the side walls I9, II, I2 and I3. Said sheet metal bottom 29 also enters a groove 3I in the member I9, as will be evident from Fig. 3. It will be noted upon reference to Fig. 5 that the spacing block 32 between the partition member 24 and the wall, or frame portion, I3 is out of alignment with the bracing member 28 and that said bracing member is provided with an enlarged portion 33, which has an inclined face 34 to prevent any sharp cornerswhere the bolted flour might collect on the pan members.

A plurality of finishing nails 35 are provided, which extend through the member 63 and into the member 24 to provide rigidity for the body portion on the side of the same having the low partition 24. The body portion of the sifter, as well as the tray, must be quite rigid to assure a close fit between the stacked trays and proper alignment of said stacked sieves. The stacked sieves, in order to prevent any escape of flour between adjoining edges thereof, are provided with facings of plush, or similar pile material, 36 to provide a form of gasket between the same, which, of course, must run around all the top edges of the walls I 0, II, I2 and I3. Metallic reinforcing strips 31 are also provided on each of the members 22, I4, 28 and I! to prevent Lmdue wear thereof in use.

The tray member forming the detachable portion of each sieve, is made up of a rectangular frame having the members 38 and 39 provided on a pair of opposed sides thereof, and the members 4D and 4! on the other pair of opposed sides. The members 4!! and 4! extend beyond the member 39, as will be evident from Figs. 1 and 2, and the ends thereof are received in re cesses 42 in the frame members Ill. The members 40 and M are provided with grooves 43 and 44 running the full length thereof, and said grooves are adapted to receive either the tongues, or ribs, 26 or 23, as the case may be. Thus in the arrangement shown in Fig. 1 and in the upper part of Fig. 3, the groove 44 receives the tongue 23 and the groove 43 receives the tongue 26, while in the arrangement shown in Fig. 2 and in the lower part of Fig. 3, the groove 43 receives the tongue 23 and the groove 44 receives the tongue 26. This makes the tray member of universal application, no matter which type of body portion, that shown in Fig. 4, or that shown in Fig. 5, is used.

The frame member 33 of the rectangular frame of the tray member is provided with a laterally outwardly projecting tongue, or rib, 45, which is received in the groove I8, said rib 45 being located adjacent the bottom edge of the member 38. The member 39 is provided with a groove 46 in the bottom face thereof, receiving the tongue, or rib, I6. It will be seen that the interfitting portions I8 and 45, and I6 and 46, will hold said tray-like member from movement in a lateral direction and in a vertical direction, also, at the left end thereof, as shown in Fig. 4. The tongue and groove connections between either the member 40 or 4!, and the members 25 and I3, will prevent lateral movement of the detachably mounted tray-like member perpendicularly to the direction in which such movement is prevented by the tongue I6 and the groove 46. Thus when these parts: are interfitted,

the tray member will be in fixed position in the body portion. Furthermore the tongue and groove connections will provide tight joints between the tray member and the body portion at the engaging edges of the walls 38, 39 and 40 or 4|, thus preventing any flour from passing between the tray and body portion at these points. .5 l

The detachable tray member is. further provided with a strip 41, extending along the side of each of the members 40 and 4| providing a shoulder adjacent the grooves 43 and 44, and also providing a shoulder spaced a very slight distance below the top edge of the members 40 and 4| and 48, the strip 41 being slightly less in height than the frame members 40 and 4|. The top edge of the frame member 38 aligns with the top edges of the strips 41, as does also the top edge of the frame member 39. The top faces of the strips 4'5 and of the frame members 38 and 39 are utilized for securing the bolting silk 49 thereto in any desired manner, said silk being usually secured by tacking. The lower, or opposite, faces of the members 38 and 39, and the strips 40 and 4|, as well-as the lower faces of the transverse bracing members 50 and, 5| having their ends seated-in grooves 52 in the members 49 and 4| and in grooves 53 and 54 in the members 38 and 39, are utilized for securing a reticulated wire member 55 to the tray, said wire member being, preferably, stapled to all of said strips, frame members and bracing members so as to hold the same rigidly and stiffly in a stretched condition, forming a stiff, rigid,

perforated partition for the bottom side of the tray portion of the sieve. A space is thus formed in the tray portion, which is bounded on the lower side, by the wire cloth member 55, and on the upper side by the bolting silk 49, and in this space loose cleaner members of a bolt-like character, or of any other desired shape, such as the members 56, are confined, said cleaner members bouncing around on the stretched wire bottom 55 as the bolter is agitated, striking against the silk 49 to keep the same cleaned.

It will be obvious that the wire 55 can be removed without removing the silk 49, or vice versa, and that the silk, which is very easily damaged, and which it is desirable to not remove unless it is absolutely necessary, can be left in place and the wire 55 removed to remove the cleaner members 56 and replace the same with new ones, in case this is found to be desirable.

The frame member 39 of the detachable inner tray-like member is provided with a groove 51,

in which the edge of the bracing member l5 fits to aid in guiding the tray-like member into proper position. The tray-like member is assembled with the body portion by first inserting the tongue 45 in the groove l8, then the frame member is swung downwardly, the grooves 43 and 44 receiving the tongues 28 and 23, as the case may be, the interfitting portions l5 and 51.

guiding the tray member in the proper position that said grooves and tongues, or rib portions, will move into interfitting relation, the tongue 56 finally entering the groove 46 to cause the interfitting engagrfient of the tray member and body portion. In order to firmly secure said tray member in fixed position in the body portion the screws 58 are provided, extending through the member I4 and into the frame member 39, and the screws 59 are provided extending through the wall portions I2 and into the frame members 38. There are only five screws used for securing these parts together, three screws 58 and two screws 59. In order to disassemble the parts, all that is necessary is to remove the screws and then tap with ahammer, or similar member, on the blocks 60, which are provided to form lugs on the projecting ends of the members 40 and 4|, whereupon the tray member will be moved upwardly in a reverse direction to that in which it was moved in assembling the parts to move said tray member to such a position that a pull thereon inan upward direction, and in a direction to separate the tongue 45 from the groove l8, will completely disengage the tray member from the body portion, the entire operation taking only a little more than a minute or so. Thus it will be seen that a worn tray member' can be replaced by a new, or repaired, tray member in only a few minutes and that these tray members will fit either of the two body portions shown herein, The top edges of the strips 40 and 4| are provided with the pile fabric 36 to provide tight joints between the portion of the tray member to which the flour is fed for bolting and the passages between the walls II and I3 and said tray, to prevent unbolted fiour 85 main body portion having an imperforate bottom, a tray portion of less height than said body portion having a perforated bottom, and means for demountably mounting said tray portion within the confines of said main body portion in fixed position, comprising closely interfitting tongue and groove portions on one end of said main body portion and one end of said tray portion holding said tray portion from vertical movement relative to said main body portion, closely interfitting tongue and groove portions on said main body portion and said tray portion on the other end and both sides of said main body and tray portions holding said tray portion from transverse movement relative to said main body portion in a plurality of directions perpendicular to each other, and means for securing said tray in interfitted relationship with said body portion.

2. In a bolter sieve, a body portion having a frame and a bottom, said frame comprising a member having a groove in the inner face thereof, a member at the opposite side of said frame having a rib on the upper edge thereof, and a pair of parallel members extending perpendicularly to said first mentioned members having ribs on the top edges thereof, a tray portion having a frame and a perforated member spanning said frame, the frame of said tray portion comprising .a member having a laterally projecting rib fitting closely in said groove, a member at the opposite side of said tray frame having a groove closely receiving the rib of the member of said body portion at the opposite side of the frame of said body portion to said member having the groove on the inner face thereof, and parallel frame members extending perpendicularly thereto having grooves therein closely receiving the ribs in the pair of ribbed members of said body portion, and securing means for holding said tray portion in such close interfitted position on said body portion.

3. In a bolter sieve, a body portion having a frame and a bottom, said frame comprising a member having a groove in the inner face thereof, a member at the opposite side of said frame said frame, the frame of said tray portion comprising a member having a laterally projecting rib fitting closely in said groove, a member at the opposite side of said tray frame having a groove closely receiving the rib of the member of said body portion at the opposite side of the frame of said body portion to said member having'the groove on the inner face thereof, and parallel frame members extending perpendicularly theree to having grooves therein closely receiving the ribs in the pair of ribbed members of said body portion, and securing means for holding said tray portion in such close interfitted position on said body portion, one of said parallel ribbed members being much shorter than the other thereof but the grooves in said parallel grooved members of said tray portion being of equal extent, whereby said tray members can be mounted on said body portion no matter on which side thereof said shorter ribbed member is located.

4. In a bolter sieve, a rectangular shallow tray-like body portion having partitions defining a chamber of less area than said body portion spaced from all except one of the sides of said body portion, a bottom for said chamber and "'a detachable rectangular frame of less height than said body portion engaging the marginal portion of said chamber and defining a tray coextensive in area with said chamber, sifting means carried by said frame, and means for detachably securing said frame in interlocking fixed, tight relation nested within said body portion, comprising interfitting tongue and groove portions on said body portion and said frame, said interfitting portions being provided on all the sides of said frame and the partitions and side of said body portion engaged by said frame and comprising a groove in the inher face of said side of said body portion receiving a tongue projecting forwardly from the corresponding side of said frame to permit said frame 3 be swung into and out of interengaging relation with said body portion, and means for securing said tray against swinging movement relative to said body portion.

5. In a bolter sieve, a rectangular shallow tray-like body portion having partitions defining a chamber of less area than said body portion spaced from all except one of the sides of said body portion, a bottom for said chamber and a detachable rectangular frame of less height than said body portion engaging the marginal portion of said chamber and defining a tray oo-extensive in area'with said chamber, sifting means carried by'said frame, and means for detachably securing said frame in fixed, tight relation within the confines of said body portion, comprising interfitting tongue and groove portions on said body portion and said frame, said interfitting portions being provided on said partition, one side of said body portion and all the sides of saidframe and being so arranged that said tray can be engaged in interlocking relation with said body portion by a swinging movement of said tray about one of said interfitting tongue and groove portions irrespective to which of two opposed sides of said chamber are adjacent the sides of said body portion, and means for securing said tray in interfitted relationship with said body portion.

' WILLIAM E. NORVELL. 

